It is a little bit early (here) but I have my Troy-Bilt lawnmower with Honda engine just about ready to go for the season. I took the blade off and got it sharpened, put a new oil filter in and a new spark plug, and I even oiled the wheels where light oil is required. I decided not to change oil and put gasoline in until right before I start mowing. I got some fuel stabilizer for the gasoline. I checked out the plug and I think the engine (Honda 160 cc) is running a little rich. How do you set the carb to lean it out a little? I live at almost 5000 foot elevation.